Device for reducing sheet metal



April 1941- T. $ENDZIMIR 2,237,794

DEVICE FOR REDUCING SHEET METAL Filed May 12, 1937 9 sheets-sheet 1INVENTOR. Than/.52 5291021114112 ATTO RN EYJ.

April 3,1941- 'r. SENDZIIMIR 2.237.794

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Filed llay 12, 1937 9 Sheets-Sheet 4 INVENTOR.

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April 1941- T. sENDzmm 2.237.794

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Filed May 12, 1957 9 Sheets-Sheet a lNVENTR. IAasusz SENazIM/E.

ATTORN EYS.

April 8, 1941. 1-. SENDZIMIR 2.237.7 4

navrcn FOR REDUCING SHEET METAL Filed Hay 12, 1937 9 Sheets-Sheet 6T140505: SENOZIMIR.

1 76. 1 INVENTOR.

ATTORNEYS Awfi fi W41. 2.237.794

T. SENDZIMIR DEVICE FOR REDUCING SHEET llETAL Filed May 12, 1937 9Sheets-Sheet INVENTOR. 739051152 SENaZIMIE,

ATTORNEYS.

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April 1941- T. SENDZIMIR v 2.237.794

DEVICE FOR REDUCING SHEET METAL Filed May 12, 1937 9 Sheets-Sheet. 3

INVENTOR. 23405032 Sam/02 0112.

ATTORNEY.S

April 8, 1941. I

1'. SENDZIMIR 2.237.794

navxcs FOR nsnucme smm 1mm.

Filed May 12, 1937' 9 Sheets-Sheet a INVE 0R.

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BY MQPM ATTORNEYS. 4

Patented Apr. 8, 1941 UNITED STATES PATENT OFF-ICE 2,2 7,194 DEVICE FORREDUCING SHEET METAL Tadeuu Sendzlmir, Paris, France, assignor to l'heAmerican Bolling Mill Company, Middleto at. Ohio, a corporation of OhioApplication May 12, 1937, tie No. 14 2,2i'l

Y 19 Claims. (ill Bil-iii lily invention relates to means for reducingmetal by falling tndtompriswinpertahfit nisrn which is automatic orsemi-automatic ih" No. 31,697 filed July 16, 1935; Serial Nofiljmd diedJuly 16, 1935; and Serial No. 83.534 died June 4, 1936. In theseapplications it have described a certain process oi rolling stripmaterial, wherein the rolling operation, the elongation of a strip maybemaintained constant in spite oi variations of temper and gauge andwherein certain means driven in a predeterned relationship with the millprovide a pre--- determined, but controllable feeding-in speed for thestrip, as wellas a predetermined and controllable feeding-out speed,thus permitting, in conjunction with the use of working rolls of verysmall diameter and rigidly supported ultimately by means of the millframe, the rolling of strip with great flatness and extreme accuracy inspite oi the variations in the rolling pieces which have been mentioned.

These teachings may be employed in connection with the presentinvention.but are not neeemarily limitations thereon, as will beciearly set torthhereinafter.

In constructing a mill of the character to which the present inventionrelates, two or more stands of working rolls may be combined in onerrame. Regarding the several stands as constituting a train of workinginstrumentalities, it willbe seen that as to any particular mill apreceding mill can act as a positivefeeding-in means, while a suceedingmill can act as a positive feeding-out means and the advantages of theformer invention secured with less over all apparatus. A difference inthe process lies in this that in. the system of my former applicationthe feeding-in and feeding-out devices were es- 'sentially deviceshaving no reducing function,

whereas in the'present case. as respects some of the pairs of workingrolls at least, the feeding-in and feeding-out devices have a reducingfunction,

so that'compensationsin rolling conditions can produce under theinfluence of varying tensions, a constant rate of elongation, whichcompensa- 'tions rn iay be occurrinp simultaneously at more thanonestandpl woriting rolls.

It must he recogniz edthatihc sction ot a. pair oi reducine rolls,especially of a small-diameter,

is not exactly the same as that or a ieedinp de vice havingsubstantially no reducing function. a is due to the slippase oi thestrip within the roll bite which varies both with the tension oi thestrip in trout and after the rolls, as well as with the pressure.

at is meant here is that it will act as such ior this purpose, that isfor leading the metal at constant predetermined proportion of velocities--se.that the stripwili elongate uniformly and be independent clifrehularitieiiin thieleness teni V.

per'and other characteristics of the raw material. However, with a millas described in this application, the reducingrolls act on the strip in.succession and it will be clear that it a plurality oireducine rolls areconsidered, their action on the strip resembles very closely the actionor a non-reducing feeding device, as they pull the strip -lointly and.ieintly----neutralize any cause (such use. thick spot on thestrip)which may afiect accurate and uniform reduction.

" I have iound that by combining in one frame or stand two or more pairsoi! working rolls of the character described, I obtain very valuableeconomies-in the weight and size of the mill, since'thesupporting beamsor structural framework can be made to support simultaneously two ormore working rolls. the'reaction of which at least partiallycounteracteach other. The resultant force in the beam. is therefore smaller thanit would otherwise be and the structure of the mill does not need to beunduly heavy.

An obvious economy lies in the fact that, n such a device the feeding-inand feeding-,outd vices which do not have a reducing function arerequired, so that in most instances but one feedlug-in and onefeeding-out device need be provided.

Still another important vantage lies in the driving means for aplurality of mills. In a machine of the type described a certainpercentage of reduction may be first decided upon for each pair ofrolls, and a common rigid geared drive may then be provided for all ofthem, this drive being suitably connected with the feeding-in andfeeding-out devices. Applicant prefers for this purpose, to adopt apercentage of reduction comfortably below the best reduction which couldbe obtained in each pass, so

simplification and adof the torque transmitted.

It will be readily understood that with a mechanism in which the rigiddrive is correctly ad- Justed, the same general rolling principles willapply as those set forth in the co-pending applications aboveenumerated. Thus tension of a high order per unit of strip section mayexist between the feeding-in and the feeding-out machines and the rolls,and also between each adjacent pair of working rolls. Yet such tensionFig. 4 is a sectionalview of a portion thereof taken along the lines 4-4of Fig. 3. Fig. 5 is a sectional view through the driving means for amill of the type shown in Fig. 2.

Fig. 6 is an end elevational view with parts in section of the mill ofFigs. 2 and 5.

Fig. 7 is an end elevational view with parts in section of the mill ofFig. 1.

Fig. 8 is a top plan view of the mill-of Figs, 2, 5 and 6.

Figs. 9 and 10 are respectively vertical and horizontal sections of aparticular type of mill drive which I find advantageous to use.

Figs. 10 and 11 are sectional views. on an larged scale, of a type ofindivi aware-331i;-

tion as shown Figrfa:

is merely a result of certain proportions of VeIQcL-HJ FigTIZ is asectional view taken along line ties imparted to the strip and is notcapable in itself of influencing the velocity of any given working partof the mill. However, elongation may be maintained constantly at apredetermined value, the tensions varying as may be required toaccomplish the predetermined elongation. Of course, a condition ofcorrect adjustment would be upset with any such mechanism if any one ofthe elements should be disturbed. For example, if a pair of workingrolls were substituted in any given mill for a pair of larger diameter,the condition of adjustment would not be the same. Inmy mail-adjustmentwithin certain limits can be ,corrected by the adjustment of the rollpass of one or more pairs of rolls.

I have solved the main difiiculty connected with the operation of asystem of this sort. This dimcu ty is to ascertain, during the actualworking of the mechanism, which if any of the pairs of rolls needsspecial adjustment and if it does, how much adjustment is needed. Mysolution is based upon actually accomplished the reduction it wasintended to accomplish, it is bound to require a certain torque to doit. If the ratio of reduction is upset, however, slightly, the tensionsboth in front of and behind the rolls are altered and so also is theactual work of reduction accomplished by the rolls. All three of thesefactors tend to change always in the same direction; that is to say theydo not counteract each other. Therefore it is possible to provide foreach a simple means to give a constant measurement The operator, in theoperation of the mechanism, therefore, has only to see that the measuredtorques do not vary too far from predetermined values, by suitably ad-55 lusting the roll clearance or screw-down so called, on one or more ofthe pairs of rolls in accordance with the torque measurements. All ofthis can be done during the continued operation of the mechanism.

Various objects of been setforthhereinabove, or will be apparent to oneskilled in the art upon reading these specifications, I accomplish bythat certain construction andarrangement 'of parts of which I shall nowdescribe certain exemplary embodiments. For clarity reference is nowmade to the drawings wherein:

Figure 1 represents a sectional view through a millembodying myinvention. V

Fig; 2 is another sectional view through a mill of slightly differentcharacter.

Fig. 3 is. a sectional view on an enlarged scale of a type of individualmill construction as shown on Fig. 1.

6 my invention which have mechanism, however, such 30 the fact that whena pair of rolls pair of working rolls ,0 rows of backing rings i2i2 ofFig. 11.

By reference to Figs. 1 and 2 it will be noted that my mill comprises ingeneral a housmgwfliich at 6, then between the parts 3 and 2 over asheave marked 7, back between the parts 2 and i and over a feeding-outdevice indicated generally at 8. I have shown mills indicated at A, A,B, B, etc. In-Fig. 1 four such mills are shown, two operating on thestrip 5 during its downward passage and two operating on the strip 5during its upward passage. In Fig. 2 I have shown nine mills compressedin the same stan Now it will be noted,-that-,the member 2 is common tothe several mills and supports oppositely directed pressure strains,whereby this part does not need to be so heavy. Moreover it will benoted that the mills are oia type in which the forces applied to theouter mill frame members I and 3 are not wholly normal to the axis ofthe frame members and therefore in part counteract each other. The millframe or housing comprises the parts i, 2 and 3 and is either made ofone piece of metal, or of several parts which are solidly and rigidlyfastened together in any way desired.

As to the mills themselves, I prefer to use such constructions as areshown in greater detail in Figs. 3 and 4 and 11 and 12. Modifications inthese structures may be made without departing from the spirit of myinvention. The various structures in general are, described and claimedin my co-pending applications referred to above. They differ from eachother in various ways, such as in the number of elements which back upthe 0 Figs. 3 and 4 and 11 and 12, it being understood that thoseparticular structures do not constitute a limitation upon my inventionas hereinafter claimed.

I have shown in these figures a mill, having a housing portion 3. .Apair of working rolls 9 and in are indicated as operating upon the strip8. In the particular mill shown on Figs. 3 and 4, the roll I0 is backedup by a pair of intermediate rolls ii and I! which in turn contact threeparallel l9, molmted on shafts l1, l5, l1, and interspaced withdisc-like bearing members'l8 resting directly in circular channelsprovided in the beam 3 of the mill stand. Clamps I are bolted to saidbearing members ll jointly forming a bore for the necks of shafts i7 andIi.

. The mill housings are so constructed 'thel 'The common shaft isshownin Figs.

face it carries teeth which pending case may be employed here. Whenrolling hot-rolled-stock of heavier gauges, such as /2 or I prefer touse such feeding-in devices as do not bend the stock, one or more pairsof pinch rolls, for example. Or I may dispense with the use of thefeed-in device entirely, as with such heavy stock the several firstpairs of reducing rolls taken in conjunction, play the role of afeeding-in device for the finishing group of rolls.' Ordinarily thestrips are welded together, always the last end of the preceding to thefirst end of the following coil, as at 6a to avoid threading the milleach time a coil is finished and secure less interruption in operation.

The feeding-out machine has been indicated generally at 8 and this againmay be as shown or it may comprise any of those devices which have beenset forth in my co-pending applications hereinabove referred to. Thestrip may proceed I to a shear 28 and may be coiled up alternately intodifferent coils as at 29 and 30.-

Considering the assembly of mills and feeding devices thus far setforth, it will be noted that the first mill in the train is positivelyfed by the feeding-in device 6 and that each successive mill in thetrain is fed by the fore-going mill. as at 3| and 32 as to guide thefirst end of the strip from one mill to another. It is preferable thatfrom the point of its entry into the first pair of rolls until itemerges from the finishing rolls, the strip will be covered with a bathof oil. The construction of my mill is such that the entire interior ofthe mill housing may be submerged in oil which not only lubricates andcools all of the bearings and all bearing surfaces, but also lubricatesand cools the strip and washes away any foreign material on its surface.To facilitate this, the return sheave I is preferably contained in anoiltight housing or sump 33. Oil may be delivered to the entrance andhousing by means indicated at .34 and 35 and will flow down between thehousing members I, 2 and 3 to the sump 33, whence it may be withdrawnthrough a pipe 36. The oil is, of course, circulated rapidly and may becooled and filtered outside of the mill after withdrawal from the byfriction, so as to ly connected by shafts48 and 48 with the workingrolls of a mill. By this arrangement side forces are neutralized andonly torques are transmitted and I am able to transmi large forces by agearing which occupies very little space, being particularly limited inthis respect as the shafts 44, 49 have practically the same diameter asthe reducing rolls themselves, and the introduction of this type of agear box greatly improves this mill. With the type of mill as shown onFigs. 1, 3 and 4, I prefer to drive the intermediate rolls II and [2which in turn, drive the working rolls ll be able to use working rollsof such a small diameter as would not stand the necessary torque. InFig. 7 I have shown the shafts 48 and 49 connected directly to theintermediate rolls II and I2. The length of the shafts 48 and 43 will besuch as to permit Slight displacement of the rolls II and i2 andeliminate the necessity for universal joint drives, although such drivesmay be employed if desired. It will be understood, of course, that wheredesired, the rolls II and I! for replacement purposes may be providedwith separable couplings for attachment to the shafts 48 and 49. In Fig.7 it will be seen that I have made my mill oil-tight for purposeshereinabove described by side plate means 50 and 5| and that suitableglands 52 are provided where the shafts 48 and 49 pass through the plate5i.

In the drives for the mill each of the individual drives connected withthe shaft 33 are calculated for the particular speed ratio requiredfor'the individual mill taking into account the diameter exit portionsof the mill pipe 33 and before re-delivery to the spouts 34 and 35. Itis preferable to provide means for pumping the oil in and out veryquickly so as to avoid loss of time in case an adjustment or repair tothe mill or a change of rolls is necessary.

Allof the workingrolls excepting preferably a t st stand, are driven byfixed gearing from one common source of power. This is illustrated bestin Figs. 5 and 6 where the main mill motor is indicated at 31 and.drives a common shaft 33. is connected by worms 39 to driving means 40for the several rolls on the train. The particular power transmittingdrive 9 and 10 where the shaft 33 is shown as slidably keyed to the worm39. This worm meshes with the member 40 which is journaled by suitablebearing means 4| in a housing 4!. The member 40 is teethed on its outersurface to mesh with the worm 33. On its inner surmesh with three pinions 43, 44 and 45. The p rpose of this particular type of gearing is tominimize the conversion of torque to displacement forces on the drivegears. It will be seen that each of the gears 43, 44 and are drivenfromboth sides. As a consequence they do not need heavy bearings in endmembers 43 and 41 of the housing 42. An adjacent pair of gears, e. g. 43and 44 may be directwithin very narrow limits of the working rolls andthe speed of the strip (as determined by previous elongation as well asthe entering speed) of such pair of rolls. Since each of the mills inthe stand can effect a reduction upon the strip, it will be obvious thateach successive mill be geared tooperate at a higher speed than thepreceding mill.

The diameter of the rolls must also be taken into consideration sincethe most economical way oi using the rolls would seem to be to startwith a new pair of working rolls on the first or roughing mill and thenas they wear transfer them to successive mills in the train, thefinishing mill having rolls always of the smallest diameter, so as to beable to use the reducing rolls to the very end of their useful life, andyet have the range of roll diameter, for each individual reducing mill,which makes the use of this rigidly geared drive possible.

Referring again to Fig. 9 the worms 33 may be slidably keyed to theshaft 38. Each worm is supported in radial and thrust bearings 53 and 54in the housing member 55. One of the thrust bearings at least isprovided with a thrust measuring ring 56, or pressure indicating ringwhich Thus may be of any of several known types. it may be a compressorbody filled with a liquid or a body containing a piezo-electric crystalor a magnetic stress measuring device or the like.

justment of the roll pass while it is running in a way which has beenindicated above. Thus in will be clear, such an adjustment can beaccomplished by automatically acting devices set in mo tlon by thepressure indicating means.

The main motor 31 is also connected with the ifeeding-in and feeding-outdevices 6 and 8 respeetively as will be described, and finally may becaused to drive the final pair of working rolls in the stand. Any directmechanical action be tween the motor 31 and such devices may beemployed. For convenience in the mill illustrated, a piston-hydraulicdrive has been adopted which, excepting for a very insignificant amountoi leakage of oil past the pistons, is the substantial operatingequivalent of a train of gears. In addition to its fixed ratio of drive,however, it

can easily be made to have an adjustable stroke and when so made, hasthe further advantage at being variable by infinitely small stages itnecessary. Such a transmission always comprises two parts, the one beinga pump, the other a motor. The pump furnishes oil under pressure to themotor so that the motor is bound to turn euactly in proportion with thequantity of oil supplied. Hydraulic transmisson mechanism of thisgeneral type is available on the open market and, therefore, is notherein described in detail.

By reference to Fig. 8 it will be seen that the motor 31- drives bymeans of chains 51, a variable stroke hydraulic pump 58 which furnishesoil to two motors, 59 and 69, each having variable strokes. Theparticular connections 58a, 59a and too between this pump and theseveral motors have not been carried through on the drawings but will bereadily understood by the skilled worker in the art. The first of thesemotors is a motor 59. This motor is connected with the ileeding-outdevice 8 by means of a pair of gears ti; but is also connected with thefeeding-in device 6 through a chain drive 6| the sprockets ilor which,62 and 83, are proportioned in size in a way appropriate to theparticular elongations desired. The chain sprocket 63 is cut'or formed.on the outside of a ring gear. The planetary or satellite gear isindicated at 64, the spider of which 6311 is connected directly to oneor the shafts of the feeding-in device 6. The sun wheel or center wheel64a of the planetary transmisslon is connected through a shaft 65 andgears at to another hydraulic device indicated at 61. in this devicethere is combined both a hydraulic motor I! (which drives the shaft 55through the pair of gears 66) and a hydraulic pump I i. The

pump H is driven through a chain drive 88 or other suitable transmissionfrom the motor 59.

It will be clear that with this arrangement, when the pump ll is set atzero stroke, the sun wheel 01 the satellite gearing 64 will not turnIand thereiore the transmission GI between the feeding-in andfeeding-out devices will be entirely rigid as it it were a trainoigears.

when an adjustment oi this fixed ratio is necessary, the stroke of thepump portion oi the hydraulic transmission 61 will be so adjusted as toiurnlsh enough oil to the motor portion of the transmission to make thesun pinion or the planetary gearing 64' turn at a desired speed so as toadd to or subtract from the original ratio. However, when suchadjustment has been made the new ratio will likewise be positive andunyielding as if it were a train of gears. This system of positive andadjustable transmisison has been discussed in detail in the co-pendingapplications for Letters Patent, hereina'bove referred to.

The second motor is the motor 69. As shown most clearly in Fig. 5 thismotor is coupled by means 10 to the last pair of working rolls in themill combination. For simplicity in this application 1 have consideredthe motor 89 as being driven by oil from the-pump i8, 'although'inpractice it may be simpler to use a separate pump for it. The motor isof exactly the same piston type as has hereinbefore been discussed andhas an adjustable stroke. With the same quantity oi oil per minute thesmaller the stroke the more rapid the motor will turn. The whole drivearrangement which I have shown and described permits one to start with astrip of raw material or the desired gauge, within the limits actuallymet in practice and to carry it down to substan-- tially any gaugedesired, always maintaining the proper velocities and consequently theproper tensions between the feeding-in device and the first pair orworking rolls, .then between each pair of rolls and the next one andfinally between the finishing pair 01 rolls and the feedingout device.

The purpose or providing separate drives for the final mill is to permitchanges of gauge without over all readjustment. This may be accomplishedin my system by eliminating the operatring effect or one or more oi! thelatter mills in the train. This can be done by opening up the mills orcan be done by removing the working rolls. The final pass is given bythe final mill with the separate drive giving a very high degree orflexibility of operation.

While I have described in some detail a certain type 01 driving means,it will be understood that others can be employed if desired. It isevident that the mill can be made to work with an entirely rigid gearconnection for example irom the feeding-in device through all theworking rolls down to and including the feeding-out device; but theratio between the feedin -in and feeding-out devices of the mills beingthus set at a fixed ratio which cannot be varied, only one definitereduction can be obtained. Thus with a givenmaterial it would bepossible under these circumstances to roll to but one finished gauge.sired, a thinner starting piece would have to be employed. On thecontrary in the arrangement which I have particularly described or anarrangement including some transmission means of equivalent flexibility,I can produce almost any specific reduction desired. This can beaccomplished by adjusting the final pass on the finishing. rolls and bythe omission of the operation of one or more preceding mil-ls as I haveindicated. Naturally this adjustment applies only to the making orlesser reductions than the maximum. A certain possible maximum reductionfor the mill cannot of course, be exceeded; but the mill may be soconstructed as to be capable of a maximum reduction in excess ofcommercial requirements.

0n the other hand, the individual pairs oi rolls or my mill may bedriven by other flexible Where a lighter finished gauge was demeans.without departing from my mill frame invention.

They may, for instance, be driven, each pair of rolls, or even each roll(from opposite sides of the mill), by a piston-type ydraulic motor,while the feeding device or devices are similarly driven. In such case,an absolute rigidity of maintaining the speed relationship of all theseinstrumentalities can still be preserved, while the reduction by eachindividual pair of rolls can be adjusted at will. same as the tension infront and after the rolls; and so the sive to buy. shall be capable ofbeing utilized better and give a higher reduction than with the geardrive as first described.

Or else individual or group electric motors may be used, employing suchspeed control means as are available. In this case all the advantages ofthe frame construction and roll support are there, but the predeterminedspeed relationship cannot be obtained with the same accuracy and withouta lag, and through accelerations and stops, as in the case of the driveshereinabove described. Such electric drive may, however, give tolerablygood results for many purposes.

As far as the housing or frame of the mill is concerned it isessentially a one piece housing: but it can also be made of severalpieces fastened together by bolts or other means of sufilcientstrengthso that under conditions of full load on all rolls, there is still aconsiderable pressure on all parts of the surfaces of Junction. Theframe is characterized by the fact that the roll supporting beams arenot loosely connected with the rest of the frame with it. that is tosay, the resistance of the bending forces which such beams ofier isstill further increased by their rlgid connection with other parts ofthe frame. This principle has also been described in the applicationsreferred to. The frame, as shown in Fig. 2 shows a staggered arrangementof the working roll assemblies. In

mill, although more expen-- but from one solid body of all it permitsthe saving of material in the frame. Secondly. it makes it very easy towork in a complete bath of oil as has been described. Thirdly, thebottom pulley gives the strip an opportunity to cool down sufficientlyespecially near the surface after the roughing treatment and beforeentering the finishing group of rolls.

Finally there is the important advantage of dividing the mill and itsoperations into two floors. The mechanics, roll grinders, and adjustmentmenparry on their operations on the lower floor as illustrated, whilethe handling of without department from the spirit of it.

the strip'both in raw and finished condition is carried on on an upperfloor. Thus the several operations do not interfere with each other.-

Although not shown in the drawings, it is. of course, preferable toprovide for the welding of the raw strip into one continuous lengthbefore it enters plished with any suitable mechanism. However, my millis not restricted to the rolling of a continuous supply of material andstrip stock of finite length may be sent through it if desired. I havealready explained how the mills in the frame are caused to beself-threading. For this purpose also I provide in connection with thereturn sheave I suitable guide means II for leading the strip from onemill section to the other. 4

- Modifications may be made in my invention Having thus described myinvention, what I claim as new and desire to secure by Letters Patentis: l. A method of reducing strip metal which consists in passing itsuccessively through two or more pairs of reducing rolls while drivingsaid reducing rolls at a fixed ratio of speed to each other. controllingthe rate of feed of the strip metal to the first pair of reducing rollsby a non-reducing, positive feeding instrumentality and controlling therate of withdrawal of the metal from the last pair of reducing rolls bya Fig. 1 there is an opposite arrangement. On non-reducing. positiveinstrumentality, so that both figurm it will be apparent, however, thatthe feeding-in and feeding-out of the metal to much metal and space issaved on all beams 5 the several pairs of reducing rolls bears a fixedwhich support rolls lying on the inside of the mill ratio of speed tothe speed of the reducing rolls. frame. Not only is one beam in thisposition 2; That method of reducing strip metal which enough insteadoftwo, but also such an interconsists in passing a strip successivelythrough mediate beam can be made .thinner and lighter than would bepossible with an outside beam because the greater part of the forcescounterbalance each other. The savings in weight. on the outside beamssupporting two adjacent rows of backing rings, like the beam H in Fig. 2is not so pronounced as with the inside beams like 6. but still it isquite considerable.

The mill illustrated in Fig. 1 is shown as having only four pairs ofworking rolls but is indicated as having also the intermediatesupporting rolls which have hereinabove been described in detail. Theprovision '02 these rolls avoids even theslightest marking that the in-.dividual supporting rings might produce on. the working rolls as theybore directly against the working rolls. Excepting for thisconsideration and considerations of space, the number of workafeeding-in apparatus having substantially no 5 reducinglfunction, thenthrough at least two feeding-out appara reducing function ing rolls inany given mill combination will usually be determined by considerationsof the great-= est reduction that the mill may be called upon toproduce. "I'hearrangement of the rolls in such a way that the stripfirst passes down- .wardly through a series of mills then runs around ashows and goes upwardly again through a series of mills is not essentialbut it pairs of'reducing rolls, and finally through a feedingwutapparatus having substantially no reducing function and causing thespeeds of all of the mentioned instrumentalities to bear a certainpggieterihined constant relationship to each 0 i;

3. That-method of reducing strip metal which consists in passing a stripsuccessively through a feeding-in apparatus having substantially noreducing function, then through at least two pairs of reducing rolls,and finally througlp a and causing the speeds oi all 4. In a rollingmill assembly a housing, a plurality of interspaced rolling means insaid housoffers some important advantages in itself. First anon-reducing, positive feeding-1n apple ratus and a non-reducing,positive feeding-out apparatus, and positively acting mechanical mothemill. This may be accom-' 4 having substantially no housing, saidhousing comprising a plurality or beams for supporting said workingrolls throughout their length, one at least of which beams is located toact as a supporting means common I to interspaced pairs of workingrolls.

"l. A continuous rolling mill comprising a housing, a plurality ofpairs, of reducing rolls located in said housing, saidhousing havingportions acting as a common support for interspaced pairs of saidreducing rolls substantially throughout their working length, saidreducing roll pairs so arranged in said housing that'a strip ofmavariations in load, and .means for separately driving the last pair orworking rolls. a

13. In a rolling mill a housing comprising beams parallel to the workingrolls, a plurality of interspaced working rolls mounted in said housingand supported in their length by said beams for housing and supported intheir length by said rolling a strip passing therethrough, said beamsbeing shaped intermediate said pairs of working rolls to lead a strip ofmaterial being operated upon from one pair of working rolls to the next.

l4. In a rolling mill a housing comprising beams, a plurality of workingrolls located in said beams in interspaced parallel series whereby astrip or material to be operated upon can be caused to pass twicethrough said housing in opposite vertical directions in said interspacedseries of working rolls, said beams being shaped terial being acted uponfirst passes through said housing in one direction between at least onepair of reducing rolls and then passes in the opposite direction throughsaid housing between one other pair of reducing rolls.

p. A continuous rolling mill comprising a housing, a plurality of pairsor reducing rolls located in said housing, said housing having portionsactling as a common support for interspaced pairs or said reducing rollssubstantially throughout their working length,.said reducing roll pairsso arranged in said housing that a strip of material being acted uponfir t passes through said housing in one direction between at least onepair of reducing rolls and then passes in the opposite direction throughsaid housing between one other pair of reducing rolls, said mill alsocomprising a feeding-in device, a feeding-out device and a sheave overwhich said material runs intermediate its passages through the housing.

d. A common drive for several pairs of reducing rolls situated in onehousing and comprising a single drive shaft with a plurality o1 pinionskeyed thereto, a plurality of -gears meshing with cold pinions, eachgear being connected to a pair oi working rolls in said housing, and adevice l'or continuously indicating the torque transmitted by it fittedto each of said pinions.

id. In a continuous rolling mill a plurality 0! rs of reducing rolls, acommon drive for said pairs of reducing rolls, said drive operating tointermediate said working rolls to lead said strip of metal from onepair of working rolls to the other, a sheave mounted to conduct saidstrip from one series of working rolls to the next, and guide meansiorconducting said strip about said sheave. v

15. A method of reducing stripmetal, which consists in passin itsuccessively through two or more pairs of reducing rolls in tandem, saidpairs of rolls being backed up throughout their length .on stationarysupporting means, the said stationary means serving fixedly tointerspace said pairs of rolls and maintaining the contour of the saidreducing rolls in spite of substantial variations or rolling pressures,and, driving said reducing rolls at a fixed ratio oispeed to each otherduring the rolling operation.

' 16. A method or reducing strip metal, which consists in passing itsuccessively through two or more pairs of reducing rolls in tandem, saidpairs of rolls being backed up throughout their length on stationarysupporting means, the said stationary means serving fixedly tointerspace said pairs of rolls and maintaining the contour of the saidreducing rolls in spite oi! substantial variations or rolling pressures,driving said reducing rolls at a fixed ratio of speed to each otherduring the rolling operation, controlling the rate of feed 01' the stripmetal to the first pair of reducing rolls by a non-reducing. positiveIeeding maintain a ii-xed ratio of speeds between said several pairs ofreducing rolls, and means for measuring the torque transmitted by saidcommon We to each of said several pairs of reducing rolls, whereby inaccordance with such measureents, adjustment or the roll passes may bemade. Y

. ii. In a continuous mill 0. non-reducing, p nitlve feeding-in device,a plurality of pairs oi working rolls, and a non-reducin p itivefeeding-out device and means for transmitting torque to said severalinstrumentalities continuously at predetermined speed ratios.

it. In a continuous mill 0. non-reducing. posi tive feeding-in device, aplurality 01 h pairs of working rolls and a non-reducing. positivefeedeach of said instrumentalities excepting the last instrumentality,and controlling the rate oi withdrawal of the metal from the last pairof reduoing rolls by a non-reducing, positive feeding instrumentality,while driving said feeding in strumentalities at a fixed ratio of speedto the speed of the several rolls.

17. In a singlehousing rolling mill, containing a plurality 0! pairs oiworking rolls, arranged to operate as a tandem mill, a housing,comprising beams supporting said working rolls substantially throughoutthe working length thereor, and members connecting said beams, at leastone 01 said beams being located so as to act as a support to more thanone working roll, said workhr' rolls so supported being located in suchmanna. that the pressur es applied thereby to said mill at predeterminedspeed ratios inspite of 7 of strip material is between said supportinmembers through a pluralityot pairs of working rolls.

' 19. In a single housing rolling mill, containing a plurality 01' pairsof working rolls, end frame members, parallel supporting members locatedbetween said end frame members, and acting as supporting meansthroughout the length of at least one roll of a plurality of pairs, sothat said supporting members are each common to a plurality of pairs ofrolls, and so that the passage of strip material is between saidsupporting'members through a plurality of pairs oi! working rolls therebeing at least three of said parallel supporting members so that thepassage or said strip material is at least twice through said millbetween said end frame members in opposite di rection. I

TADEUSZ SENDZIMIR.

